Updated

Thousands of ethnic Rohingya Muslims are trying to cross from Myanmar into Bangladesh, following an attack by Rohingya militants in western Myanmar that left 89 people dead in a dramatic escalation of communal violence that has plagued the region.

The militants launched the attacks overnight Thursday on more than two dozen police and border outposts. The office of Myanmar's leader, Aung San Suu Kyi, said military and border police responded to the attacks — which left 12 security personnel and 77 Rohingya dead — by launching "clearance operations."

A Rohingya leader at an unregistered camp in Bangladesh's Cox's Bazar district said he had heard that some 100,000 Rohingya had gathered along the border to try to enter Bangladesh, but the number could not be confirmed.